Duracell MN21 (A23/23A) Specialty Alkaline — 12V Power for Remotes, Access Systems, and Sensors

The Duracell MN21—also known as A23 or 23A—is a compact, 12-volt alkaline battery designed for small transmitters and access devices that need a high-voltage punch in a tiny package. You’ll find MN21 in car remotes, keyless entry fobs, garage door openers, wireless doorbells, and select security sensors. If your device lists “A23,” “23A,” or “MN21,” this battery delivers the reliable activation and range your transmitter expects.

Standout Benefits

• High-voltage output (12V): Ideal for RF transmitters that require strong signal bursts.
• Compact size: Fits slim remotes and miniature housings.
• Dependable shelf life: Keep spares on hand for quick, confident swaps.
• Leak-resistant construction: Helps protect delicate circuit boards and contacts.

Where MN21 Is Used

• Car key fobs and alarm remotes
• Garage door openers and gate controls
• Wireless doorbells and security sensors
• Small RF gadgets and specialty electronics

Technical Profile

• Chemistry: Alkaline
• Voltage: 12V
• Designations: MN21 / A23 / 23A
• Typical dimensions: ~28.5 mm length × ~10.3 mm diameter
• Type: Primary (non-rechargeable)

MN21 vs. Coin Cells and Other 12V Types

MN21 is a cylindrical 12V battery assembled from small alkaline cells. It is not interchangeable with 3V coin cells (CR2032/2025/2016) or other 12V formats (e.g., A27). Always match the exact code your device specifies for proper fit and radio performance.

Installation Guide

1. Identify the code: Look for “MN21,” “A23,” or “23A.”
2. Observe polarity: Insert with the “+” end toward the positive symbol in the tray.
3. Clean the contacts: Remove oils or dust with a dry, lint-free cloth.
4. Seat firmly: Ensure the battery door or cap closes completely.
5. Test range: After installation, check remote function at normal distance.

Storage, Handling, and Safety

• Store at room temperature in original packaging.
• Do not carry loose cells in pockets with coins/keys.
• Keep away from children and pets; dispose of used batteries responsibly.

Maximizing Performance

• Avoid pressing buttons inadvertently (e.g., in pockets), which drains charge.
• Keep contacts clean to maintain transmitter strength.
• If range is weak, re-seat the cell and verify compartment closure.

Troubleshooting

• Remote still weak: Re-sync with the vehicle/opener if required by the manufacturer.
• Intermittent operation: Clean contacts; ensure correct battery code (MN21 vs. A27).
• No response: Confirm polarity and check for mechanical wear in the button pad.

FAQs

Is A23 the same as MN21?

Yes—A23, 23A, and MN21 are common cross-references for the same 12V alkaline format.

How long does MN21 last in a car remote?

Runtime varies with use frequency, RF range, and temperature. Infrequent use extends life; frequent lock/unlock cycles and cold weather reduce it.

Can I use rechargeable substitutes?

No—most remotes are designed for primary alkaline MN21 cells; rechargeable substitutes are not recommended unless the device explicitly supports them.

Summary

Duracell’s MN21 (A23/23A) packs dependable 12V power into a tiny cylinder perfect for key fobs and access controls. Install the exact code, keep contacts clean, and avoid accidental button presses to maintain range and reliability.